Mr. Gasket 2476BK Domestic Thermocap Combines a pressurized radiator cap with a thermometer element that eliminates potentially dangerous guesswork Lets you know exactly when your coolant temperature is low enough to safely open your radiator cap To install just take off your old cap and screw on the new one If the temperature gauge indicates that the coolant is too hot just rinse the radiator with cool water until the temperature drops into a safe zone Anodized black finish